Edinburgh, 1917: Headstrong Highland lass Mary Stewart is a vibrant woman forced into the world's oldest profession in order to provide for her ailing father and younger sister in the city's Old Town. When her uncle, a well-to-do solicitor with political aspirations, thinks that her presence might impede his lofty ambitions he gives her a way out with dignity: a one-way ticket to the frontier town of Anyox, British Columbia, where nurses are needed to care for injured soldiers returning from the war.

Mary agrees to depart Scotland and leaves her sister in the care of her uncle, but finds that a past like hers is not easy to escape, and that living on the frontier has more challenges than even the darkest streets of Old Town. She must survive by her quick intelligence, but that is a quality that few women were allowed to reveal.

Danial Neil's historical epic Dominion of Mercy combines the gritty feel and attention to detail of HBO's Deadwood with the Canadian sensibility of Guy Vanderhaeghe's frontier trilogy.